Question

I have read about FileInputStream and I found that it have read method where it will read the byte data of the file.

What I want to know is what types of byte data does it read? Meaning does it use ASCII or Unicode or any other types?

Answer 1

what i want to know is what types of byte data does it read? meaning does it use ASCII or Unicode or any other types?

As far as FileInputStream and its methods are concerned, there is only one “type” of data. And that type is “a sequence of bytes (or octets)”.

Any other “types” are for another library (or application code) layer to deal with.

The “types” you refer to as ASCII and Unicode are character encodings (roughly speaking). (In fact, Unicode is NOT an encoding at all … and doesn’t exactly make sense in this context. Encodings for Unicode have names like “UTF-8” and “UTF-16” and so on – see http://en.wikipedia.org/wiki/Comparison_of_Unicode_encodings.)

Anyway, the standard way to “deal” with text file types (i.e. sequences of characters in some standard character encoding scheme) is to use a Reader class. And there is a wrapper class called InputStreamReader that is specifically designed for reading character data from an InputStream.

Other non-textual “types” of data are handled by classes like ZipInputStream, InflaterInputStream, GZIPInputStream, the image reader classes, and so on.